CVE-2026-40372

ASP.NET Core Elevation of Privilege Vulnerability

Published Apr 21, 2026 CVSS 3.1 · 9.1 Critical EPSS 11.2% KEV · Not listed
Description
Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9mv3-2cwr-p262 Microsoft Security Advisory CVE-2026-40372 – ASP.NET Core Elevation of Privilege
Ubuntu USN Ubuntu USN USN-8215-1 .NET vulnerability
Ubuntu USN Ubuntu USN USN-8216-1 .NET vulnerabilities
History
Type Values Removed Values Added
First Time appeared Microsoft visual Studio 2026
CPEs cpe:2.3:a:microsoft:visual_studio_2026:*:*:*:*:*:*:*:*
Vendors & Products Microsoft visual Studio 2026
Type Values Removed Values Added
Description Improper verification of cryptographic signature in ASP.NET Core allows an unauthorized attacker to elevate privileges over a network.
Title ASP.NET Core Elevation of Privilege Vulnerability
First Time appeared Microsoft
Microsoft asp.net Core
Weaknesses CWE-347
CPEs cpe:2.3:a:microsoft:asp.net_core:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft asp.net Core
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
microsoft
Published
Updated
Oct 15, 2026, 3:53 PM
Reserved
Apr 11, 2026, 11:06 PM
Status
Modified
Published
Apr 21, 2026, 8:16 PM
Modified
Oct 26, 2026, 9:10 PM
Severity
Critical
Public date
Apr 21, 2026, 7:20 PM